USN-5652-1: Linux kernel (Azure) vulnerabilities
It was discovered that the framebuffer driver on the Linux kernel did not verify size limits when changing font or screen size, leading to an out-of- bounds write. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33655) Domingo Dirutigliano and Nicola Guerrera discovered that the netfilter subsystem in the Linux kernel did not properly handle rules that truncated packets below the packet header size. When such rules are in place, a remote attacker could possibly use this to cause a denial of service (system crash). (CVE-2022-36946)
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-image-azureto a version that resolves this vulnerability.Fixed in Ubuntu Pro - Upgrade
Upgrade
ubuntu/linux-image-4.15.0-1151-azureto a version that resolves this vulnerability.Fixed in Ubuntu Pro
Event History
Frequently Asked Questions
What is the vulnerability ID for this advisory?
CVE-2021-33655.
What is the severity of CVE-2021-33655?
The severity of CVE-2021-33655 is not specified in the advisory.
How can a local attacker exploit this vulnerability?
A local attacker can exploit CVE-2021-33655 to cause a denial of service (system crash) or possibly execute arbitrary code.
Which versions of the Linux kernel are affected by CVE-2021-33655?
Versions 4.15.0.1151.138 and 4.15.0-1151.166~16.04.1 are affected by this vulnerability.
Where can I find more information about CVE-2021-33655?
You can find more information about CVE-2021-33655 on the Ubuntu security advisory page.